Improved furnace for extracting zinc from its ores



A. THOMA.

Zinc. Furnace.

Patented June 8, 1869'.

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ALOIS THOMA, OF NEW YORK, N. Y.,

ASSIGNOR TO THE AMERICAN ZIN COMPANY, OF SAME PLACE.

IMPROVED FURNA-CE FOR EXTRACTING ZINC FROM ITS ORES.

Specication formingA part of Letters Patent N0. 91,051, dated J une 8, 1869.

To all whom it may concern:

Beit known that I, ALoIs THOMA, of New York, in the county of New York and State of New York, have invented a new and Improved Furnace for Extracting Zinc from Ore; and I do hereby declare that the following is a full,

clear, and exact description thereof, which will enable others skilled in the art to make and use the same, reference' being had to the accompanying drawings, forming part of this specification.

The object of this invention is to remove the inconveniences heretofore existing in the production of zinc, and to simplify the labor connected therewith.

Heretofore only muffle' and pipe furnaces were used for that purpose. Their management is difficult, and only experts could be used to work them. The operation was consequently expensive, on account of the labor. It was furthermore expensive on account of fuel. From six to twelve tons of coal or twenty cords of wood were required for the production of one ton of zinc. Wood was very seldom used, and other f uel, such as lignite or peat, was never employed, the furnaces not being adapted to its use. The heat to which the laborers were exposed, especially in summer-time, was almost intolerable, and added to the difculty of operation, particularly in southern climates, where, at least in theUnited States, the most zinc appears to be stored. Muffles and tubes are, furthermore, expensive to make, and require frequent renewal, as they are fragile and easily destroyed, thereby occasioning a loss of time and material. All these inconveniences are overcome by my improved furnace, which is of substantial construction, not apt to get out of repair, and applicable to all kinds of fuel. any ordinary workman, and will require much less fuel than the devices for the same purpose heretofore in use. y

My invention consists, chiefly, in the arrangement of a furnace in which the gases of burning fuel are burned, to separate the zinc from the ore.

In the accompanyin g drawings, Figure 1 represents a horizontal section of my improved zinc-furnace, the plane of section being indicated by the line w w, Fig. 2. Fig. 2 is a ver- It can be easily operated by tical longitudinal section of the same, the plane of section being indicated by the line y y, Fig. 1. Fig. 3 is a vertical transverse section of the same, the plane of section being indicated by the line z z, Fig. 1. Fig. 4 is a vertical transverse section of the condensing apparatus, the plane of section being indicated by the line fr Fig. 1. Fig. 5 is a vertical longitudinal section of the condensing apparatus, the plane of section being indicated by the line y' y', Fig. 1. Fig. 6 is an end elevation of the furnace. Figs. 7 and 8 arc top views of grate-bottoms to be placed into the condenser. Figs. 9 and 10 are longitudinal sections of the same. Figs. l1 and 12 are transverse sections of the same.

Similar letters of reference indicate corresponding parts.

The furnace is L-shaped, consisting of two wings, A and B. In the wingA are produced the gases, while the wing B is the main furnace. There is another structure, C, provided alongside of the furnace B, and connected with the same bymeans of apipe, D, as shown in Fig. 6.

In the gas-generator A is arranged a step- Y shaped grate, a, on which the fuel from which the gases are produced is burnt. The grate shown is intended more particularly for coal or lignite. When peat, charcoal, or wood is to be used as fuel I would change the form of grate accordingly. The air necessary for the consumption of the fuel is introduced through a pipe, b, in which suitable dampers, or other devices for regulating the quantity of air, may be arranged.

Above the grate is formed a chamber, c, which is, by means of a channel, d, connected with the furnace B, as shown in Fig. 3. e is a door through which the grate can be cleansed. fis one for removing the ashes. Above the chamber c is arranged an opening, g, through the ceiling of the gas-generator, for the purpose of allowing the introduction of fuel. n

The products of combustion pass from the grate through the chamber c and channel d into a narrow deep chamber, It, formed at the end of the furnace B, a channel, fi, connecting the said chamber h with the main chamber of the furnace. posit all dust and ashes and pass in a pure In the chamber h the gases de-l state through the channel t', which is at the upper part of the chamber, as shown in Fig. l.

One side of the dust-chamber h is formed by the heating apparatus E, in which the air requisite for the -combustion of the gases is heated. This air enters the boxE through a pipe, j, and has to pass in a Zigzagline over a series of shelves arranged in the box, as shown in Figs. l and 2, so as to become thoroughly heated. Through a pipe, k, the air is from the boxE conducted into a compartment, l, whence it escapes into the furnace. In the pipe 7c, or at any other desired place, should bea slide, m, for regulating the quantity of air mixed with the gases.

The pressure of the air is regulated by the following apparatus: The compartment has on its inner face a narrow horizontal slot, the width of which is regulated by a plate, a, that is suspended from bolts or otherwise made upand-down adjustable. When the slot is made narrower the pressure is greater, as the quantity of air which is regulated by the damper m has to pass through it, be the slot wide or narrow. The chest l and its lateral slotted portion are supported on and protected from the heat of the burning gases by means of a partition, .0, made of fire-proof material.

The gases enter the main chamber B through the channel il. The ore is spread on the floor of the chamber B, together with some coal or equivalent substance. There is so much air mixed with the gases that only a portion of the same can be burnt, whereby the non-burnt portion is heated to such a degree that thereduction and evaporation of the zinc are most effectually obtainedthat is, at about 22000 Fahrenheit. The hydrogenous carbonio acid, which gives off a great deal of heat, will rst be burnt. The balance of the gases will not be burnt, but will serve to reduce the zinc, and will keep it in a vaporous form, not reducing it to dust or oxidizing it.

There are small openings p p in the sides of the furnace for inspecting the contents. These openings are closed by glass plates, behind which there are metal slides, to prevent Zincdust from covering the glass.

The ore is inserted through a door, F, at one end of the furnace, together with the coaly substance with which it is mixed, and is evenly spread over the floor of the furnace. Only uuder the pipe D there is a large proportion of coal placed into the furnace, for the purpose of arresting any carbonic acid, so that the pure zinc may not by the same be again reduced into dust. There are openings qqin the sides of the furnace B, which are kept well closed, and through which the contents are well stirred, at intervals of about three hours, for the purpose of exposing the lower parts-to the action of the heat, thereby hastening the process. The gases that have passed through the furnace are, through the pipe D, carried into the condenser C. The pipe D may, by passing through water or otherwise, be cooled.

The condenser C consists of two longitudinal compartments, r and s, of which the former is surrounded by brick or stone walls, the latter by cast-iron. The zinc is, in a vaporous form, carried by the gases into the condenser. The ytwo compartments of the condenser are divided by shelves t t into serpentine channels, the shelves being perforated at alternate ends, as shown. The zinc will be properly condensed by passing along these shelves through the openings therein, and condensation may be still more facilitated by inserting the perforated plates I I, shown in Figs. 7 and 8. The vapors containing the zinc would have to nd their way between the slots of these plates, and thereby condensation will be materially facilitated. As soon as the vapors are again expanded they give off their Zinc, and before the last shelf has passed all zinc has been precipitated. All the shelves t t are inclined toward their openings, so that the Zinc deposited on them will ow down through the said openings into a receptacle, u, at the bottom of the condenser, whence it can be removed at will. The receptacle u has a contracted lower part, in which lead, should such have been in the ore, is collected, a separate opening being provided for the removal of the lead. There are openings in the sides ofthe condenser to allow the shelves to be cleansed. The gases that have been liberated from the zinc can, in a pipe, G, be conducted to any other suitable apparatus, 'where they can be utilized. They may, through a pipe, H, be allowed to escape altogether.

The gases burn well, and can be used for roasting the zinc ore, f'or driving machinery, or for other purposes.

All the surfaces in the furnace, condenser, and pipe D which come in contact with the zinc vapors should be enameled or glazed, to prevent any fine zinc from settling in rough places.

Having thus described my invention, I claim as new and desire to secure by Lettersy Patent- 1. Producing Zinc from ores that are spread within a gas-burning furnace, substantially as herein, shown and described.

2. The furnace B, when constructed as described, for the purpose of producing zinc from ore by means of the burning gases that are the products of combustion of suitable fuel, as set forth.

3. Providing the openings q gin the sides of the furnace B, for the purpose of allowing the zinc-ore to be turned over, to facilitate the process, as specified.

4. Arranging the blast-heating apparatus E as one well of the furnace B, substantially as described, so thatthe air is heated by the ascending gases, as set forth.

5. The application, to the air-heating apparatus, of the slides m and n, for the purpose of at once regulating the quantity and the pressure of the air conducted to the gases, substantially as herein shown and described.

6. The dust-detaining chamber 7L, when ar ranged between the grate a and the furnace B, substantially as and for the purpose herein shown and described.

7. The condenser C, when provided with a series of shelves, t t, Which are perforated and provided with inclined upper surfaces, substantially as herein shown and' described, for the purpose of allowing free passage for the gases, and of conducting the zinc to a certain receptacle, as specified.

8. The perforated plates I I, when inserted within the condenser, for the purpose of facilitating the process of condensation, as set forth.

' 9. So constructing the zinc-receptacle uthat lead may be collected at vits bottom and separately removed, as set forth.

10. A zinc-furnace consisting of the gratechamber A, for burning the fuel, of the furnace B for evaporating the zinc, and of the condenser C for separating the zinc from the gases, all arranged and operating substantially as herein shown and described.

ALOIS THOMA.

Witnesses: p

FRANK BLooKLEY, ALEX. F. ROBERTS. 

